The basic objectives of this study are: (a) To formulate the simplest mathematical description of the head, head-neck junction and the spine consistent with explaining the clinical observations on traumatic injury to these parts of the human body. (b) To perform the experimental studies to obtain the biomechanical data to implement the models developed. These include the distribution of inertial and material properties as well as the failure criterion of the tissue involved. (c) To study the effects of neuromusculature in acceleration injuries through experimental EMG and model analysis. (d) To construct a mechanical model of the head to simulate the measurement of intra-cranial pressure as a prelude to in vivo measurements of primates. (e) To develop possible design solutions to control and prevent the above injuries.